Chucking machine



Dec. 8. 1925.- 1,564,353

. Z7VVENTOR.

EDWARD E. JHlvso/v.

A TToR/vE Y6? Dec. 8, 1925. 1,564,353

E. E. JOH NSON CHUCKING MACHINE Filed April 1; 1922 9 Sheets-Sheet 4 EDWARD E. (75HNSON 5 A T TOFPNE Y8.

Dec. 8, 1925.

E. E. JOHNSON CHUCKING MACHINE Filed April 1 9 Sheets -Sheet 5 A TTOFPNEYS Dec. 8, 1925- E. E. JOHNSON CHUCKING MACHINE 9 Sheets-Sheet Filed April 1, 1922 Dec. 8 1925. 1,564,353

E. E. JOHNSON I v CI IUCKING MACHINE Filed April 1,1922 9 Sheets-Sheet 8 Dec. 8 1925.

E. E. JOHNSON CHUCKING MACHINE Filed April 1,

1922 9 Sheets-Sheet 9 I/vvz-r/v TOR. EDWARD E. T0H/v60/v.

5 A WW M, W ATTORNE Y6.

Patented Dec. 8, 1925.

1 UNITED STATES EDWARD E. JOHNSON, OF ST. PAUL, MINNESOTA.

' CHUCKING MACHINE.

Application filed April 1, 1922. Serial No. 548,700.

To all ivlaom. it may concern:

Be it known. that I, EDWARD E. JoIrNsoN, a citizen of the United States, residing at St. Paul, in the county of Ramsey and Statev threading different portions of articles in ,2:00111bll12ltl011 with means for moving the articles from one deviceto the other, and means for partially rotating the articles while they are thus moved in order to bring different portions thereof into position for the finishing or threading opera-tion. An

object in particular is tov provide a mecha nism for screw-threading couplings internally at both of their ends. Another object is to provide means for eounterboring,'trin1- ming and smoothing the ends of the couplings before they arescrew-threaded. lVhile my mechanism is intended particularly for usejinconnection with tapping tools for internal threads, it may be used in connection with threading dies forexternally threading articles suchas stud bolts at both ends; In carrying out my invention,-I provide a plurality of tool-holding spindles underneath which a .turret is moved. step-by-step in order to bring articles carried by the turret in succession under the (spindles in which position the articles are operated upon while the turret is atrest. There are preferably two spindles carryingtrimming tools which act first and, a plurality'of spindles carrying threading tools. Provision is made for partially rotating the articles to bring different portions thereofinto position to be operated upon, this partial rotation being performed during thetime-that the turret is given its step movements: The full bjects and .:advantages of my invention .will appear in connection with the detailed description, andthenovel features embodiedzinmy inventive idea will be particularly pointed out in the claims- In the accompanying drawings which i1 lustrate a practicalform-bf.construction in I which my invention-is'e'mbodiedpFig. l is a front elevational v ew.- F1g.:-2 isazview mostly in vertical central section and with some portions omitted for cle-arness of illus tration. Fig. 3 is an end elevational view. Fig. 4: is an end elevational view of the lower part of the machine from the opposite side with relation to F ig. 1 and showing a clutch shifting mechanism. Fig. 4 is a view in section on the line 4 -4 of Fig. 4. Fig. 5 is a view in horizontal section on the line of Fig. 4. Fig. 6 is a top plan View. Fig. 7 is a view in section on the line 7-7 of Fig. 6 showing the tools at the lower portion of their movement. Fig. 8 is a View in section on the line 8-8 of Fig. 5. Fig. 9 is a view in section on the line 9-9 of Fig. 8. Fig. 10 is a view insectio'n on the line 1010 of Fig. 8. Fig. 11 is a view in see tion on the line 1111 of Fig. 8. Fig. 12 IS a fragmentary view in section on the line 1 212' of Fig. 1. Fig 13 (Sheet 5) is a viewin horizontal section on the line 1313 of Fig. 7. Fig. 14 (Sheet 5) is a view in vertical section on the line I l-14 of Fig. 1. Fig. 15 (Sheet 3) is a view in vertical sec tion on the line 1515 of Fig. 5. Fig. 16 (Sheet 3) is a view in section on the line l( i16 of Fig. 15. Fig. 17 is a fragmentarv view in elevation of a construction embodying shiftable gears whereby either right or left hand threads may be formedas desired. Fig. 18 is a view in section on the line 1818 of Fig. 17. Fig. 19 is a fragmentary view in section showing how the machine may be used for threading stud bolts.

Referring" to the constructionsho'wn in the drawings, the numeral 10 designates a driving pulley which is adapted to be driven from any suitable source of power and which ismounted on a shaft 12 in such -manner that it may be connected thereto or disconnected therefrom by a clutch l4.-

.22 to which is secured a hand lever 24c):-

tending up so as to be with n reach of the operator standing at the front of the machine. ings carried by the frame of the machine and secured to this shaft, is a wor1n"26 .meshing with a worm gear-QSsecured to a camshaft mounted in bearings in a The shaft 12 ismounted in bear-- casing 32. Secured to the shaft 30 as best shown in Fig. 8 are five cam members 34.

- movement of the turret as will be described later. It is needful to produce this movement in as short a time as possible,-in this embodiment it is one-eighth of a turn of cam shaft 30. The are of action of the escapement begins on center line between shafts 30 and and is completed by the wiping apart of the circular paths of the parts 46 and 48. The lever 48 is pivoted on a pin 50 and its upper end 52 is connected by a universal joint, best shown in Figs. 15 and 16 (Sheet 3) comprisinga radial cylindrical socket in lever end 52 in which a slotted plug 53 is journaled for both rotary and reciprocating motion, and within the slotted plug 53 a bearing block 54 journaled in the slot and on radial pin 57 of lever 56, with one end of the lever 56 having a cylindrical portion 58 mounted for rotative movement on a bushing 60 through which passes a bolt 62. To the other arm of the lever 56 which is angularly disposed with relation to the first arm is secured a resilient pawl arm 64 by means of a U-bolt 66 as shown in Fig. 5. Attached to the pawl arm at 68 is a pawl 70 which is adapted to engage in succession a plurality of pins 72, constituting a ratchet, for rotation, there being ten of these in the embodiment shown. Suilicient over-travel is given to the resilient pawl arm 64 by the escapement lever 48 to insure a complete step-by-step movement of ratchet pins 72, the resiliency of the pawl arm at the same time allowing a complete movement of the escapement. The revolving turret which rests on the base 88, is journaledon the tubular column 84 fixed therein and on sleeve 82, and comprises a hollow bod provided with radial spindles 90, bottom flange 78, neck 7 6 and ratchet index plate 74 and ratchet or index pins 72. A pan 306 for holding chips and coolant surrounds the turret 80 and is supported rigidly by posts 307 and bushing 60 and bolt 62 abo've and away from base '88 as shown in Fig. 15. Pan 306 has an inner flan ed edge 308 overlapped by the bottom fiange 78 of turret 80. The object of this arrangement is to provide free movement of the turret and to keep the chips and coolant from getting into the indexing mechanism below. The turret 80. as shown in Fig. 7 carries a plurality of horizontal spindles rotatably mounted thereon and which are equal in number to the index pins 72. Secured to the spindles 90 and lying within a hollow portion of the turret are pinions 92 which mesh with a bevel gear 94 secured to the sleeve 82 on column 84. Proper meshing of these gears is provided forby threaded collar 83 on sleeve 82, coacting with the annular portion of the gear 94 lying within the teeth to secure them in fixed relation. The outer portions of the spindles 9O carry holders for couplings C or other work to be operated upon as best shown in Figs. 7 and 12. These holders include sockets 96 for receiving the couplings which are held therein by bolts 98 carrying stems 100 for engagement with the couplings. Screws 81 fix the sleeve 82 and bevel gear 94- in exact position so the sockets 96 are in axial alinement with the tool spindles 196 and 238 when the turret is at rest. The outer portions of spindles 90 are preferably shouldered against the turret 80, while the hub of pinions 92 abuts the inside of the turret to fix the spindle against end play. The portion of spindle 90 surrounding the coupling O or other work'is flattened and pierced with a hole 95 to receive the removable work sockets 96. When the heads 102 of the clamping bolts are rotated in one direction, the couplings will be free to drop out, and when the heads are turned in the opposite direction, the couplings placed in the sockets will be securely held in place. The action of the pawl 70 on the index pins 7 2 gives the turret 80 which carries the, spindles 90 a stepby-step rotation, each step being one-tenth of a rotation in the einbodi' ent shown. The proportions of the gear 9 and pinions 92 is such in this embodiment that the spindles 90 are given a half rotation for each step movement. Obviously any other portion of a revolution may be arranged for. In order that the pawl 70 may operate effectively, its hook end 104 as shown in Fig. 5 is held against the index pins 72 by a spring 106 attached thereto at one of its ends, the other end 01 the spring being attached to the lever 56. In order to hold the escapement lever 48 against the projection 44, a spring 108 connects the upper end of the lever to a fixed projection 110. In order that the pawl 70 may release one of the pins 72 and properly engage the next pin on its return movement, it is provided with a cam 112 located inwardly from the hook end. This cam swings the pawl outwardly by engagement with the in which is being released until the inclined end oi. the pawl is in sliding contact with the next pin to be engaged. In order to cause the turret 80 carrying the spindles 90 to stop exactly in the proper position and to remain in this position until moved another step, the construction shown in Figs. 5 and 9 has been adopted. Two dogs 113 and 114 are pivoted at their outer ends to bosses on the ends of a bar 115 bolted to the base 88 and are normally held in alinement with each other by a spring 116 attached to projections on the dogs. Half round pins 117 depending from the dogs 113 and 114 have their flat surfaces adapted to engage with the fiat surfaces of half round pins 120 projecting up from the bar 115 as best shown in Fig. 10. These pins prevent the dogs 113 and 114 from swinging too far inwardly or toward the right as shown in Fig. The dogs 113 and 114 are separated by a gap of the proper width to receive one of the pins 72 previously referred to. Vhen one of these pins is approaching this gap, the dog 114 is'forced back in opposition to the tension of the spring 116, and when the pin reaches the gap, it will be securely locked therein, by the beveled end of the dog. In order to release the pin at the proper time, a rod 122 is attached at one end to the dog 113 and at its other end to the lever 124 intermediately pivoted to the casing 32, as best shown in Fig. 9. The end of the lever 124 which is located in the casing 32 is'adapted to be struck at the proper time by a cam arm 126 carried by the cam shaft 30. The cam 34 previously referred to which carries the projection 44 on one face carries on the other face a pair of approximately semicircular flanges 128 and 130 which are disposed oppositely to each other around the circumference of the cam with the flange 128 located nearer the center than the flange 130. These flanges operate in alternation with each other upon a roller 132 mounted on one end of a slidable rod 134. In the position shown in Fig. 4, this roller has been held up by the flange 130 and is just ready to be acted upon by the inclined end 136 of the flange 128 which pushes the roller downwardly, and it is held down by this flange until the inclined end 138 of the flange 130 engages and pushes it up again. The lower portion of rod 134 is provided with stopcollars 149, while positioned between them is the free end of lever arm 148 of shaft 150, which as shown in Fig. 2, also carries clutch yoke 152, the upper end of which engages in a groove in a clutch member feathered to shaft 162 and having opposite-toothed ends 154 and 156. Either stopcollar 149 when brought by the completed shifting of rod 134 against lever arm 148 acts to bring the clutch yoke 152 to neutral position with the clutch ends 154 and 156 out of contact. This provides a rigid metal-to-metal action between the actuating cam 34 and the clutch ends 154 and 156, to bring the last named to neutral, the necessity for which will be shown later.

According to the position of the roller 132, the clutch end 156 will at one time engage a clutch member carried by a bevel gear 158 and at another time the clutch end 154 will engage a clutch member carried by a bevel gear 160. Shaft 162 carries a spur gear 164 meshing with pinion 166 on shaft 12 from which it gets continuous rotary motion, bevel gears 158 and being journaled freely thereon. The bevel gears 158 and 160 both mesh with a bevel gear 168 which will obviously be rotated first in one 'direct on and then in the other direction, depend.- ing upon which of the clutch ends 154 and 156 is engaged. The gear 168 is secured to a vertical shaft 170 which is journaled in base 88 and extends up through and free from a'vcrtical hollow shaft 172 which will be referred to later and which extends up through the fixed tubular column 84 prevlou'sly referred to. The tubular column 84 is fixed below in base 88 and above in the hub 86 of head casing 173, in the cap 173 of which is journaled the top of shaft 170 in the combined thrust and radial bearing 175. Secured to the upper end of the shaft 170 within the head casing 173 is a spur gear 174 which, as best shown in Fig. 13, meshes with the six pinions 176, 178,180, 182, 184, and 186 which are secured respectivel to spindles 188, 190, 192, 194, 196, and 198 which are rotatably and slid ably mounted in upper bearings 200, and lower bearings 202 in head casing 173 as best shown in Fig. 7. The lower ends of these spindles are provided with heads 204 for holding tools such as tapping tools 206. The tapping tools carried by the spindles 188 and 190 are for rough tapping the holes in the work, the tapping tools carried 105 by the spindles 192 and 194 are for still further tapping the holes in the work.

while the tapping tools carried by the spindles 196 and 198 are for finishing the tapping operation. This arrangement is 110- cessitated by the fact that it is not practicable to completely tap the work by a single operation of a tapping tool. These tapping tools may be set up for producing a single size or for two different sizes of 115 holes, as will be shown later. The upper portions of the tapping tool spindles are surrounded by coiled springs 208, the upper ends of which engage lock nuts on the spindles, and the lower ends of which as 120 shown in Fig. 7 fit into sockets in a flanged lifting head 210 which as shown in Fig. 6

is of such shape as to extend over the six tapping spindles and is provided with holes through which these tapping spindles extend. This lifting head is adapted to slide up and down, on a guide 211 placed preferably in the center of gravity of the spindles it lifts, and its position is controlled in the following manner: A two-arm lever 212 no is pivoted at 213 and its inner ends engage under the lifting head, while its outer umtary end is attached to a downwardly extending rod 214 to the lower end of which is pivoted a member 216 extending slidably through a thickened portion of the casing 32 as best shown in Fig. 11.

The lower end of the member 216 carries a roller 217 which at certain times is pulled downwardly by the cam 36 previously referred to. This cam consists of a ange located on the periphery of the member 36 with the engaging surface of the cam flange consisting of ve portions 218, 219, 220, 221 and 223, the functions of which will now be described in order (it being understood that cam flange through its connections with the lifting head 210 acts to control the s1x tap spindles at the last portion of the backingout movement, then during the indexing or step movement, and finally at the beginning of the tapping operation, and that the cam flange is not acting during the greater portion of the tapping and backing-out operation). During this last part of the cycle the tapping tool retreats and unthr'eads due to the reversal of the tap spindle rotation. The portion 218 picks up the tap spindle from the lowest position as for example when no coupling or other work is being operated on and the tap spindle at this time hangs supported by the spring 208. This portion 218 is of use only when for some reason one of the holders has not been supplied with a blank coupling. The portion 219 causes a dwell with the tap spindle held up so as to give a slight upward pressure on the retreating tapping tool when it is fully backed out. The portion 220 lifts the tapping tool clear of the blank so that the indexing or step movement may be brought about. The portion 221 lets the tapping tool down on the blank while the tap spindle is rotating in forward direction and practically holds the spindle in balance so that the tapping tool can find its seat inthe blank without shock. The portion 222 lowers the tapping spindle gently while the tapping tool runs forward about two turns into the blank. The spindle-weight is transferred to the tapping tool at the passing of the portion 222 or the end of the cam. It will be noted that the tapping tool is backing out and rising during the passing of the portions 219 and 220 and is turning in the other direction about the beginning of the portion 221 so as to be running in a forward direction when it is let down upon the blank at the end of the portion 221. It will be noted also that all operations of the machine are timed from the cam shaft 30, one cycle being completed for each turn of the cam shaft. In the case of the ta ping spindles, this involves a forward an reverse direction of rotation and of endwise movement, so that it is imperameshes with a bevel gear 228 secured to the inner portion of the shaft 12. Secured to the upper portion of the shaft 172, is a spur gear 230 which meshes with two pinions 232 and 234 which are secured respectively to spindles 236 and 238 which are rotatably and slidably mounted in bearings 240 and 242, such as best shown in Fig. 7. These spindles have continuous forward rotation and are provided with heads 244 for holding trimming and counter-boring tools 246 which trim off and finish the ends of the couplings and bring them to a uniform length and diameter. The spindles 236 and 238 are normally held up by coiled springs 248 which surround them between a fixed portion of the frame and heads 250 mounted on the upper ends of the spindles as best shown in Fig. 14. In order to depress the spindles 236 and 238 at the proper time, a forked lever 252 is provided, the two branches of the fork acting on the heads of the respective spindles by means of links 254 placed between the heads and adjusting screws 256 carried by the ends of the forked lever. This lever is pivoted on a pin 258 to the head casing 173. The end of the lever opposite the forked end has attached thereto a downwardly extending rod 260, the lower end of which has a head 262 slidably mounted in a thickened portion of the casing 32, as best shown in Fig. 10. The lower end of this head carries a roller 264 which is engaged by the cam 38, the latter being a profile cam having the shape shown in Fig. 10. It is obvious from this construction that the two tools 246 will be gradually fed down upon the blanks, and when the roller drops into the depressed portion of the cam, the springs 248 will quickly lift the tools. As previously stated in the present embodiment of the invention, there are ten pins 72 secured to the index plate 74. It follows that there are ten equally spaced positions around the head casing 173, six of which are occupied by the spindles carrying thetapping tools and two of which are occupied by the trimming tools. Another one is occupied by an oil pump 266 and the remaining one which is really the initial position, is idle and is indicated at 268 in Fig. 6. This position is at the front of the machine and is the place where the couplings to be operated upon are inserted and the finished couplings are removed.

274 is provided with a handle 278 by means of which it can be turned by the operator and the plunger has a wrench socket 280 which is adapted to fit over the bolt heads 102 when the spring 272 is free to act. A forked arm 282 engages a slot between the plunger 276 and the wrench socket 280 and holds the plunger retracted while the pins 72 and the step-operated turret 80 are in motion, thus insuring that the wrench socket shall not be in engagement with a bolt head while thelatter is moved in indexing. The arm 282 is intermediately bent so as to extend pivotally through journals 284, and this arm at its outer end is bent downwardly at 286 so as to be engaged by the cam 42 as best shown in Fig. 8. This cam is so shaped that it holds the wrench retracted against the tension of the spring 272 except when a bolt head 102 is at rest in the initial position. The operator by giving the handle a turn in the proper direction' at such time partially withdraws the bolt 98 and this allows the finished coupling to drop into a chute 288. The operator then inserts the coupling blank, which is to be operated upon in the socket 96 and upon giving the handle 278 a turn in reverse direction the coupling blank is securely clamped in place. Just before the turret 80 .which carries the coupling blanks is given a step movement, the cam 42 acts on the mm 282 and causes the wrench to be retracted. The coupling blank which has been inserted is first stepped to a position directly underneath the oil pump 266 which may be termed .a dead position, since the coupling is not here acted upon. The next step brings the coupling under the first trimming tool 246 where one end is acted upon as best shown in Fig. 7. The next step brings the coupling under the second trimming tool where the-other end thereof is acted upon since the coupling is given a half rotation while making a step movement on account of the pinions 92 being in engagement with the stationary bevel gear 94. The same result is obtained while the couplings are being stepped along with a relation to the three sets of tapping tools. It will be seen that the spindles 236, 188,

' 192 and 196 operate on one end of.a blank and all the alternate spindles 238, '190, 194 and 198 on the other end, so that with proper. tooling articles with like or diflferent'threads in, like or different diameters or with right and left hand threads may produced. In order to deliver coolant to the trimming and tapping tools, the followimrmechanism is provided. Secured to the driving shaft 12 is a sprocket gear 290 connected by a sprocket chain 292 with a sprocket gear 294 which is secured to the shaft 296 of a pump 298 from the bottom of ference underneaththe head 173. From the pipe 302, nozzles 304 extend into juxtaposition to each of the tapping and trimming tools so as to deliver coolant thereto and to the coupling which is being operated upon. The coolant after it has served its purposes drops into the pan 306 from which a pipe 308 leads back to a tank, not shown, from which it is sucked up by the pump, preferably passing on its way through a suitable filtering device. The oil pump 266 in head casing 173 previously referred to as being located one step from the initial position where couplings are inserted is in the form of a cylinder which contains a piston operated by a rod. 310 connected to one end of a lever 3l2,'the other end of which is connected to a crossbar carried by the two arm lever 252. The reciprocation of the piston causes a circulation of oil in the head 173 to lubricate the gears contained. therein.

The head casing 173 completely encloses the spindle gearing and is oil-tight.

The construction shown in'Figs. 17 and 18 embodies a modification .in which alternate tapping spindles are operated by shiftable gearing so that the coupling being operated upon may be provided with right and left hand threads at its opposite ends so as to constitute a turn-buckle. This construction will be best understood by comparing Fig. 18 with Fig. 13 from which it will be observed that in "the modified form idle gears 314, 316, and 318 are interposed between the alternate tapping spindles 188, 192, and 196 and the driving gear 174. In order that the remaining tapping spindles 190, 194, and 198 may be caused to thread the blank in either right or left hand direction, they are each arranged foroperation by shiftable gearingwhich, inconnection with the spindle 190, in Fig. 18, is shown in one position in full lines and in the other position in dotted lines. Each of the spindles 190, 194 and 198 is surrounded by asleeve 320 adaptedto be oscillated by a handle 322. Extending inwardl from the sleeve 320 andmovable therewit is a prowith the gear 3281 and is also constantly to the tapping spindle. Upon moving 1n 'mesh with the gear which is secured the handle 322 in one direction or the be other, either of the gears 326 or 328 may be made to, mesh with the driving gear 174 so that the alternately disposed spindles 190, 194.- and 198 may either be driven in the same direction as the spindles 198, 192, and 196 or in the opposite direction therefrom. Since, as previously explained,

the couplings are turned end for end each time they are moved from one tapping spindle to the next, it is evident that by means of this construction the couplings may be threaded right and left hand on the opposite ends or the two ends may both be threaded in the same direction.

In the construction shown in Fig. 19, the tapping tool such as 206 as shown in Fig. 7 has been replaced by a threadin die 330 for operating upon a studbolt S which may .be held by the same clamp used in connection with couplings. The threading dies may be used in connection with all six of the threading spindles and the stud bolt will be threaded on both of its ends. When threading stud bolts, the trimming tools 246 may be modified to perform chamfering or hollow milling operations if desired.

' Obviously an article having one male and one female thread on opposite ends may be produced.

The operation and advantages of my invention have been quite fully stated in connection with the foregoing detailed description. The operator standin at the front of the machine may start an stop the same as desired by means of the lever 24. Each time that one of the work-holding sockets comes to rest in front of him, in what may be termed the initial position, he turns the handle 278 in the roper direction to release the finished artic e and after inserting a blank in the socket, turns the handle 278 in the opposite direction to clamp the blank in the socket. The step-by-step rotation of the turret brings each end of each blank in succession under the trimming and threading spindles. When the turret is at rest, a pluralitv of blanks will be operated upon at the same time, each blank being operated upon after each step movement in a manner which progressively brings it into finished condition before it reaches place of discharge.

I claim: 1

1. A chucking machine comprising spinthe dles in spaced relation for carrying screwthreadin tools, a rotatably mounted turret,

-work-ho ding devices mounted on said turret spaced from each other the angular distance between successive threading tools, means whereby said work-holding devices are given a half rotation each time while said turret is rotated the angular distance between the successive threading tools, means for moving said turret step-by-step to bring articles held by said work-holding devices in succession underneath said threading tools, and means for causing said spindles to'rotate first in one direction and then in the other. K

2. A chucking machine comprising spindles for' carrying screw-threading tools equally spaced from each other circumferential y, a rotatably mounted turret, spindles rotatably mounted on said turret around the periphery thereof and spaced from each other by a dlstance equal to' the distance be- ,tween successive threading tools, workholding devices carried by said last mentioned spindles, means whereby said 3 in dles are given a half rotation each time w ile said turret is rotated the distance between and down movements of dles in spaced relation for carrying screwthreading tools,-a rotatably mounted turret, work-holding clamps mounted on said turret, means for moving said turret stepby-step to bring articles held by said clamps in succession underneath said threadingtools, means whereby said clamps are given a half-rotation while said turret is moved the distance between successive threading tools, clamp-operating means whereby said clamps may be loosened to release threaded articles and to permit inserting of articles to be threaded and whereby said clamps may be tightened to hold the latter articles, and means for holding said clamp-operating meansretracted during step movements of saidturret.

4. A' chucking machine comprising a plurality of .spindles for carrying screwthreading tools equally spaced from each other circumferentially, a rotatably mounted turret, spindles rotatably mounted on said turret around the periphery thereof and spaced from each other a distanceequal to the distance between successive threading tools, work-holding clamps carried by said and tightening said clamps, means whereby said spindles are given a half-rotation when said turret is moved'the distance between successive threading tools, means for moving said turret step-by-stp to bring articles held by said clamps in succession underneath said threading tools, a locking device for holding said turret in 'proper position between successive steps, means for releasing said locking device, means for controlling up and down movement of said thread ing spindles, means for causing said threading spindles to rotate first in one direction and then in the other, means for holding said clamp-operating means retracted dur- Cal ing step movements of said turret, and means for bringing said clamp-operating means into operating position when not thus held retracted.

5. A'chucking machine comprising spindles for carrying screw-threading tools a rotatably mounted turret, work holdin devices mounted on said turret spaced from each other the distance between successive threading tools, means for giving said turret a step-by-step movement --to bring articles held by said holding devices in succession underneath said threading tools, means for causing said threading tools to rotate first in one direction and then in the other, a cam shaft, a cam member on said shaft having successive operating portions, and means operated by said successive portions for first picking up said threading spindles from their lowest position, then giving a slight upward movement to said threading spindles while the tools are being backed out, then lifting the threading tools clear of'the work during a step movement of said work support, then; letting the threading spindles and tools down on the work while said spindles are rotating in a forward direction, and then lowering the threading spindles and tools while the tools are rotating in forward direction.

6. A chucking machine comprising a plurality of pairs of spindles for carrying screw-threading tools equally spaced from each other circumferentially, a pair of spindles for carrying trimming tools similarly spaced from each other, means for rotating said trimming tools in forward direction, a rotatably mounted turret, spindles rotatably mounted on said turret around the periphery thereof and spaced from each other a distance equal to the distance between successive threading and trimming tools, work-holding clamps carried by said last mentioned spindles, means for loosening and tightening said clamps, pinions secured to said last mentioned spindles, a gear with which said pinions mesh, said pinions and gear being so proportioned that said spindles are given-a half rotation while said turret is rotated the distance between successive threading and trimming tools, means for moving said turret step by-step to bring articles held by said clamps in succession underneath said threading and trimming spindles, a looking device for holding said turret in proper position between successive steps, means for releasing said locking device, means for controlling up and down movement of said threading spindles, means for causing said threading spindles to rotate first in one direction and then in the other, means for feeding said trimming spindles down upon the work while said turret is at rest, means for holding said clamp-operating means retracted during step movements of said work support, and means for bringing said clamp-operating means into operating position when not thus held retracted.

7. A chucking machine comprising a plurality of pairs of spindles for carrying screw-threading tools equally spaced from each other circumferen'tially, a pair of spindles for carrying trimming tools similarly spaced from each other, means for rotating said trimming spindles in forward direction, a rotatably mounted turret, spindles rotatably mounted on said turret around the periphery thereof and spaced from each other a distance equal to the distance between successive threading and trimming tools, work-holding clamps carried by said last mentioned spindles, means ,for tightening and loosening said clamps,

pinions secured to said spindles, a gear with which said pinions mesh, said pinions and gear being so proportioned that said spindles are given a half rotation when said work support is rotated the distance between successive threading and trimming tools, a series of circularly arranged projections sccured to said turret, a pawl adapted to engage said projections and more said turret step-by-step to bring articles held by aid clamps in succession underneath said threading and trimming spindles, a locking device for holding said work support in proper position between successive steps, a cam shaft, a cam member on said shaft, means associated with said cam member for reciprocating said pawl, means also associated with said cam member for causing said threading spindles to rotate first in one direction and then in the other, a second cam member on said shaft having successive operating portions, means operated by said successive portions for first picking up said threading spindles from their lowest position, then giving a. slight upward movement to said threading spindles when the tools are being backed out, then lifting the threading tools clear of the work during a step movement of said work support, then letting the threading spindles and tools down to the work while said spindles are rotating in forward direction, and then lowering the threading spindles and tools while the tools are rotating in forward direction, a third cam member on said cam shaft, means associated therewith for feeding said trimming spindles. down upon the work while said turret is at rest, a fourth cam member on said cam shaft, means associated therewith for releasing said locking device, a fifth cam member on said shaft, means associated therewith for holding said clampoperating means retracted during step movements of said turret, means for bringing said clamp-operating means into operating position when not thus held retracted, and means for rotating said cam shaft.

8., A chucking machine comprising spindles in spaced relation for carrying screwthreading tools, a lifting head provided with holes through which said spindles extend, means for resiliently supporting said spindles with relation to said lifting head, means for reciprocating said lifting head, a rotatably mounted turret, work-holding devices mounted on said turret, means whereby said work-holding devices are partially rotated while said turret is rotated the dis-- tance between successive threading tools, and means for rotating said turret step-byste to bring articles held by said workho {ling devices underneath said threading too s.

9. A chucking machine comprising spindles in spaced relation for carrying screwthreading tools, a lifting head provided with holes through which said spindles extend, means for resiliently supporting said spindles with relation to said lifting head, a guide located in the center of gravity of said spindles and upon which said lifting head is adapted to slide up and down, means for reciprocating said lifting head, a rotatably mounted turret, work-holding devices mounted on said turret, means whereby said work-holding devices are partially rotated while said turret is rotated the distance between successive threading tools,

and means for rotating said turret step-biste to bring'articles held by said wor ho ding 'devices underneath said threading 11. A chucking machine comprising spin- I dles in spaced relation for carrying screwthreading tools, a lifting head, means for reciprocating said head in parallel with said spindles, resilient means normally holding said spindles upwardly with relation to said lifting head whereby they are given a floating suspension, devices for holding the articles to be threaded, and means for bring ing said holding devices in succession under 7 a said threading tools.

In testimony whereof I hereunto aflix my signature.

EDWARD EQJOHNSION. 

